1"""
2  Copyright (c) 2024, The OpenThread Authors.
3  All rights reserved.
4
5  Redistribution and use in source and binary forms, with or without
6  modification, are permitted provided that the following conditions are met:
7  1. Redistributions of source code must retain the above copyright
8     notice, this list of conditions and the following disclaimer.
9  2. Redistributions in binary form must reproduce the above copyright
10     notice, this list of conditions and the following disclaimer in the
11     documentation and/or other materials provided with the distribution.
12  3. Neither the name of the copyright holder nor the
13     names of its contributors may be used to endorse or promote products
14     derived from this software without specific prior written permission.
15
16  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  POSSIBILITY OF SUCH DAMAGE.
27"""
28
29
30class AdvertisedTlv:
31    """
32    Represents a TCAT Advertisement TLV, used to advertise capabilities of a TCAT Device.
33    """
34
35    DEVICE_TYPE_STATUS_TLV = 4
36    CAPABILITIES_TLV = 5
37
38    def __init__(self, type: int = None, size: int = None, value: bytes = None):
39        self._type: int = type
40        self._size: int = size
41        self._value: bytes = value
42
43    def __str__(self) -> str:
44        return f'TYPE 0x{self._type:02x} VALUE: {str(self._value)}'
45
46    def set_from_bytes(self, data: bytes):
47        self._type = (data[0] & 0xf0) >> 4
48        self._size = data[0] & 0xf
49        header_len = 1
50        self._value = data[header_len:header_len + self._size]
51
52
53class CapabilitiesTlv(AdvertisedTlv):
54    G = 0x80
55    L = 0x40
56
57    def __str__(self) -> str:
58        val = int.from_bytes(self._value, 'big')
59        return f'TYPE 0x{self._type:02x} G: {is_set(val, self.G)} L: {is_set(val, self.L)}'
60
61
62class DeviceTypeStatusTlv(AdvertisedTlv):
63    D = 0x80
64    R = 0x40
65    B = 0x20
66    T = 0x10
67    C = 0x08
68    S = 0x04
69    M = 0x02
70
71    def __str__(self) -> str:
72        val = int.from_bytes(self._value, 'big')
73        return f'TYPE 0x{self._type:02x} D: {is_set(val, self.D)} R: {is_set(val, self.R)} B: {is_set(val, self.B)} T: {is_set(val, self.T)} C: {is_set(val, self.C)} S: {is_set(val, self.S)} M: {is_set(val, self.M)}'
74
75
76def is_set(val, flag):
77    return 1 if val & flag else 0
78
79
80def _create_tlv(data: bytes):
81    res = None
82    header_len = 1
83    type = (data[0] & 0xf0) >> 4
84    size = data[0] & 0xf
85    value = data[header_len:header_len + size]
86
87    if type == AdvertisedTlv.DEVICE_TYPE_STATUS_TLV:
88        res = DeviceTypeStatusTlv(type, size, value)
89    elif type == AdvertisedTlv.CAPABILITIES_TLV:
90        res = CapabilitiesTlv(type, size, value)
91    else:
92        res = AdvertisedTlv(type, size, value)
93
94    return res
95
96
97def parse_tlvs(data: bytes):
98    res = []
99    while data:
100        next_tlv = _create_tlv(data)
101        header_len = 1
102        data = data[next_tlv._size + header_len:]
103        res.append(next_tlv)
104    return res
105